fix(exec): show MCP spawn args in trust prompt (#1165)

Author: TheGreatAxios

src/exec/runner.ts

@@ -8,6 +8,7 @@ import { type Config } from "../config/index.js";
 import {
   shellTimeoutFromSettings,
   toolWatchdogFromSettings,
+  type MCPServerConfig,
 } from "../config/settings.js";
 import {
   codexProfileFromProviderName,
@@ -162,6 +163,17 @@ const logger = getLogger([LOG_NAMESPACE_ROOT, "exec"]);
 
 const SELECTED_PROVIDER_FAILURE = "SelectedProviderFailure";
 
+export function formatExecMcpTrustQuestion(server: MCPServerConfig): string {
+  return (
+    `Trust local MCP server "${server.name}" for this project?` +
+    (server.command !== undefined
+      ? `\nCommand: ${server.command}${(server.args ?? []).length > 0 ? ` ${(server.args ?? []).join(" ")}` : ""}`
+      : server.url !== undefined
+        ? `\nURL: ${server.url}`
+        : "")
+  );
+}
+
 export async function refreshSelectedProviderCredential<T>(
   refresh: () => Promise<T>,
 ): Promise<T> {
@@ -706,12 +718,7 @@ export async function runExec(config: Config): Promise<ExecResult> {
       requestMcpTrust: async (server) => {
         if (!interactive) return false;
         const result = await promptOperator(
-          `Trust local MCP server "${server.name}" for this project?` +
-            (server.command !== undefined
-              ? `\nCommand: ${server.command}`
-              : server.url !== undefined
-                ? `\nURL: ${server.url}`
-                : ""),
+          formatExecMcpTrustQuestion(server),
           ["Trust and connect", "Deny"],
           true,
         );

tests/unit/exec/runner.test.ts

@@ -12,6 +12,7 @@ import {
   createExecToolCallGate,
   createExecToolPromoter,
   execUserFailureMessage,
+  formatExecMcpTrustQuestion,
   refreshSelectedProviderCredential,
   resolveExecDirectorOverlay,
   runExec,
@@ -70,6 +71,58 @@ function bareConfig(task: string): Config {
   } as unknown as Config;
 }
 
+describe("exec MCP trust prompt", () => {
+  test("shows a stdio command with literal space-joined args", () => {
+    const question = formatExecMcpTrustQuestion({
+      name: "filesystem",
+      command: "npx",
+      args: ["-y", "@modelcontextprotocol/server-filesystem", "/tmp/work"],
+    });
+
+    expect(question).toBe(
+      'Trust local MCP server "filesystem" for this project?\nCommand: npx -y @modelcontextprotocol/server-filesystem /tmp/work',
+    );
+  });
+
+  test("shows only the stdio command when args are omitted", () => {
+    expect(formatExecMcpTrustQuestion({ name: "local", command: "node" })).toBe(
+      'Trust local MCP server "local" for this project?\nCommand: node',
+    );
+  });
+
+  test("shows only the stdio command when args are empty", () => {
+    expect(
+      formatExecMcpTrustQuestion({ name: "local", command: "node", args: [] }),
+    ).toBe('Trust local MCP server "local" for this project?\nCommand: node');
+  });
+
+  test("shows an HTTP server URL", () => {
+    expect(
+      formatExecMcpTrustQuestion({
+        name: "remote",
+        type: "http",
+        url: "https://mcp.example.test/api",
+      }),
+    ).toBe(
+      'Trust local MCP server "remote" for this project?\nURL: https://mcp.example.test/api',
+    );
+  });
+
+  test("does not show environment secrets", () => {
+    const question = formatExecMcpTrustQuestion({
+      name: "private",
+      command: "private-server",
+      env: { API_TOKEN: "super-secret" },
+    });
+
+    expect(question).toBe(
+      'Trust local MCP server "private" for this project?\nCommand: private-server',
+    );
+    expect(question).not.toContain("API_TOKEN");
+    expect(question).not.toContain("super-secret");
+  });
+});
+
 describe("formatCaughtError", () => {
   test("prefers Error.message and stringifies other values", () => {
     expect(formatCaughtError(new Error("disk full"))).toBe("disk full");